1. Field of the Invention
The present invention pertains to a support assembly for a marine propulsion unit and, more particularly, an assembly for rotatably supporting a propulsion unit of an inboard/outboard marine propulsion system relative to a transom of a watercraft.
2. Discussion of the Prior Art
Inboard/outboard marine propulsion systems for watercraft are widely known in the art. Such propulsion systems include an engine which is positioned inside the watercraft and a propulsion unit which is positioned outside the watercraft. Output drive from the engine is transmitted to the propulsion unit by linking an output shaft of the engine with an input shaft of the propulsion unit through the transom of the watercraft. It is also known in the art to rotatably mount a casing which houses the propulsion unit about the common axis defined by the output shaft of the engine and the input shaft of the propulsion unit so as to selectively shift the propulsion unit between above-water and in-water positions. Such prior art arrangements are represented by U.S. Pat. Nos. 3,111,108 and 3,136,286.
Such marine propulsion systems which permit the propulsion unit to be rotated relative to the watercraft provide various advantages. For instance, when docking or storing the watercraft, the propulsion unit can be positioned above the water level to prevent adhesion of barnacles and the like to the propulsion unit. In addition, when foreign matter becomes lodged in the propeller or impeller, this matter can be easily removed by positioning the propulsion unit in a convenient above-water position.
In the above-referenced marine propulsion systems of the prior art, the propulsion unit is supported by a bracket attached to the transom of the watercraft. The bracket has a first set of bearings which allows the rotation of the casing of the propulsion unit relative to the bracket and a second set of bearings on the casing which supports the input shaft of the propulsion unit. In these prior art arrangements, the first and second sets of bearings must be positioned at spaced intervals which requires a rather long casing for the propulsion unit. Based on this requirement, a considerable space in the fore-aft direction is required to accommodate the propulsion unit. Therefore, such prior art arrangements do not provide a marine propulsion system which is compact in the longitudinal direction.